Remembering Lost just makes me angry. If I ever watch it again, I'll end it when they open that hatch and just assume they unleashed the smoke monster that then killed them all. That's a better ending to anything they could have come up with and at least I won't have to suffer through inane plots, stupid characters who never talk to each other, pointless literature and pop culture references thrown in to make the audience feel clever, and a thousand and one further mysteries thrown in just to keep viewers coming back every week.
With regards to your point above Hansen regarding having a detailed story plan being overrated - I can't say I agree, especially if your story relies on a big mystery or central mythology. Of the 4 shows I'm aware of that have such a mystery at their heart that I've seen, all have failed to deliver on those expectations generated when they began it - X-Files, ALIAS, Lost, and BSG - and we know all of them didn't actually have an answer in place before they started down that road. Furthermore, another initially successful TV show, Heroes, then went completely off the rails because the subsequent seasons, which they hadn't planned for at all, were rushed into production. The record isn't good.
The 'making it up as you go along' can only work if you're really fucking good at writing and/or you know your material really well. The most successful multi-arc series of them, Babylon 5, is masterful in how well connected all the bits are - season 1 is a text-book example of how to lay the groundwork and every season expands and extends beautifully. But not all of it was set in stone, and JMS routinely had to negotiate ways of getting through major obstacles such as actors leaving the show. But then... that was his skill and planning as well, he had written 'trap doors' for all of his characters which allowed him alternative stories should they leave.
Imagination will often carry us to worlds that never were. But without it we go nowhere. - Carl Sagan
